This invention relates to an improved clip especially useful as a closure for packaging material.
Numerous patents disclose apparatus for attaching a U-shaped clip about packaging material. Typical of such patents are the following:
______________________________________ Reg. No. Inventor Title Issue Date ______________________________________ 2,880,419 Tipper Apparatus for Fastening 4/7/59 Casings with Staple-Like Fast- eners 3,543,378 Klenz Clipping Apparatus 12/1/70 3,583,056 Klenz Clipping Device 6/8/71 Re. 30196 Velarde Single Piston Operated 1/22/80 Clip Device ______________________________________
The clip which is attached about the package of material has over time evolved from a simple U-shaped clip into a clip of various unique structures and configurations. Numerous prior art patents teach such constructions including the following:
______________________________________ In- Issue Reg. No. ventor Title Date ______________________________________ 3,400,433 Klenz Clipping Device 9/10/68 3,584,347 Klenz Clipping Device 6/15/71 3,611,509 Klenz Method and Apparatus for Forming 10/12/71 Clips ______________________________________
Among the patents which teach the construction of various clips are those which show that the cross sectional shape of the wire from which the clip is formed may have a profound effect on the operability and effectiveness of the clip. For example, U.S. Pat. No. 3,400,433 discloses a generally rhombohedral cross section for a clip. Another patent, namely Klenz U.S. Pat. No. 3,584,347, discloses still another cross sectional shape associated with a packaging clip.
With improved and more sophisticated packaging materials, improved clip designs have evolved. It is, for example, desirable to provide clips which require less material in order to save the cost of material as well as the weight of packaging. Also, it is desirable to maintain or improve the mechanical holding ability of the clips which will be used in packaging equipment. Further, it is desirable to provide clips which may be formed by roll forming techniques. In order to have economy of manufacture. Still another desirable feature associated with clips is that they be operable or usable in existing clip attachment machines. With these objectives in mind, the present clip construction was devised.